BUG: fixes get_instance_attributes for Flight objects containing a Rocket object without rail buttons

[leogrosa]

Pull request type

• Code changes (bugfix, features)
• Code maintenance (refactoring, formatting, tests)
• ReadMe, Docs and GitHub updates
• Other (please describe):

Checklist

• Tests for the changes have been added (if needed)
• Docs have been reviewed and added / updated
• Lint (black rocketpy/ tests/) has passed locally
• All tests (pytest tests -m slow --runslow) have passed locally
• CHANGELOG.md has been updated (if relevant)

Current behavior

When calling the function get_instance_attributes() and passing a Flight object that contains a Rocket object without rail buttons as the argument, it crashes. More specifically, it crashes when trying to calculate the rail button forces (__calculate_rail_button_forces).

Stack trace:

instance = <Flight(rocket= <rocketpy.rocket.rocket.Rocket object at 0x11370c410>, environment= <rocketpy.environment.environment.Environment object at 0x110e2b680>, rail_length= 5.2, inclination= 85, heading = 0,name= Flight)>
owner = <class 'rocketpy.simulation.flight.Flight'>

    def __get__(self, instance, owner=None):
        if instance is None:
            return self
        cache = instance.__dict__
        try:
            # If cache is ready, return it
>           val = cache[self.attrname]
E           KeyError: 'rail_button1_normal_force'

rocketpy/mathutils/function.py:3531: KeyError

During handling of the above exception, another exception occurred:

self = <rocketpy.mathutils.function.funcify_method.<locals>.funcify_method_decorator object at 0x1112cf4d0>
instance = <Flight(rocket= <rocketpy.rocket.rocket.Rocket object at 0x11370c410>, environment= <rocketpy.environment.environment.Environment object at 0x110e2b680>, rail_length= 5.2, inclination= 85, heading = 0,name= Flight)>
owner = <class 'rocketpy.simulation.flight.Flight'>

    def __get__(self, instance, owner=None):
        if instance is None:
            return self
        cache = instance.__dict__
        try:
            # If cache is ready, return it
            val = cache[self.attrname]
        except KeyError:
            # If cache is not ready, create it
            try:
                # Handle methods which return Function instances
>               val = self.func(instance).reset(*args, **kwargs)
E               AttributeError: 'list' object has no attribute 'reset'

rocketpy/mathutils/function.py:3536: AttributeError

During handling of the above exception, another exception occurred:

flight_calisto = <Flight(rocket= <rocketpy.rocket.rocket.Rocket object at 0x11370c410>, environment= <rocketpy.environment.environment.Environment object at 0x110e2b680>, rail_length= 5.2, inclination= 85, heading = 0,name= Flight)>

    def test_get_instance_attributes_with_flight_without_rail_buttons(flight_calisto):
        """Tests if get_instance_attributes returns the expected results for a
        flight object that contains a rocket object without rail buttons."""
    
>       attributes = utilities.get_instance_attributes(flight_calisto)

tests/unit/test_utilities.py:185: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
rocketpy/utilities.py:682: in get_instance_attributes
    members = inspect.getmembers(instance)
/opt/homebrew/Cellar/[email protected]/3.12.3/Frameworks/Python.framework/Versions/3.12/lib/python3.12/inspect.py:607: in getmembers
    return _getmembers(object, predicate, getattr)
/opt/homebrew/Cellar/[email protected]/3.12.3/Frameworks/Python.framework/Versions/3.12/lib/python3.12/inspect.py:585: in _getmembers
    value = getter(object, key)
rocketpy/simulation/flight.py:2850: in max_rail_button1_normal_force
    return np.abs(self.rail_button1_normal_force.y_array).max()
rocketpy/mathutils/function.py:3540: in __get__
    val = Function(source, *args, **kwargs)
rocketpy/mathutils/function.py:147: in __init__
    self.set_source(self.source)
rocketpy/mathutils/function.py:225: in set_source
    source = self.__validate_source(source)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <[AttributeError("'Function' object has no attribute '__dom_dim__'") raised in repr()] Function object at 0x113aee3c0>
source = array([], dtype=float64)

    def __validate_source(self, source):  # pylint: disable=too-many-statements
        """Used to validate the source parameter for creating a Function object.
    
        Parameters
        ----------
        source : np.ndarray, callable, str, Path, Function, list
            The source data of the Function object. This can be a numpy array,
            a callable function, a string or Path object to a csv or txt file,
            a Function object, or a list of numbers.
    
        Returns
        -------
        np.ndarray, callable
            The validated source parameter.
    
        Raises
        ------
        ValueError
            If the source is not a valid type or if the source is not a 2D array
            or a callable function.
        """
        if isinstance(source, Function):
            return source.get_source()
    
        if isinstance(source, (str, Path)):
            # Read csv or txt files and create a numpy array
            try:
                source = np.loadtxt(source, delimiter=",", dtype=np.float64)
            except ValueError:
                with open(source, "r") as file:
                    header, *data = file.read().splitlines()
    
                header = [label.strip("'").strip('"') for label in header.split(",")]
                source = np.loadtxt(data, delimiter=",", dtype=np.float64)
    
                if len(source[0]) == len(header):
                    if self.__inputs__ is None:
                        self.__inputs__ = header[:-1]
                    if self.__outputs__ is None:
                        self.__outputs__ = [header[-1]]
            except Exception as e:  # pragma: no cover
                raise ValueError(
                    "Could not read the csv or txt file to create Function source."
                ) from e
    
        if isinstance(source, (list, np.ndarray)):
            # Triggers an error if source is not a list of numbers
            source = np.array(source, dtype=np.float64)
    
            # Checks if 2D array
            if len(source.shape) != 2:
>               raise ValueError(
                    "Source must be a 2D array in the form [[x1, x2 ..., xn, y], ...]."
                )
E               ValueError: Source must be a 2D array in the form [[x1, x2 ..., xn, y], ...].

rocketpy/mathutils/function.py:3243: ValueError

New behavior

The function get_instance_attributes() doesn't crash when passing a Flight object that contains a Rocket object without rail buttons. More specifically, the method __calculate_rail_button_forces() correctly returns a constant Function object mapping to 0.

Breaking change

• Yes
• No

Additional information

The test tests/integration/test_flight.py::test_time_overshoot fails locally.

[Gui-FernandesBR]

This PR looks great.

Only two small things tombe done:
1 - update the CHANGELOG file
2 - link this PR with the corresponding issue.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.49%. Comparing base (83aa20e) to head (f6db943).
Report is 25 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #786      +/-   ##
===========================================
+ Coverage    76.42%   79.49%   +3.07%     
===========================================
  Files           95       96       +1     
  Lines        11090    11501     +411     
===========================================
+ Hits          8475     9143     +668     
+ Misses        2615     2358     -257     

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[Gui-FernandesBR]

@leogrosa , just a reminder you have to update the CHANGELOG.md file before we can merge this PR.

This PR should be added to the next release (this weekend).

[leogrosa]

@Gui-FernandesBR, CHANGELOG is now updated and the conflict has been resolved.
I'm just worried about the test that didn't pass locally.

[Gui-FernandesBR]

@Gui-FernandesBR, CHANGELOG is now updated and the conflict has been resolved.
I'm just worried about the test that didn't pass locally.

@leogrosa can you specify which tests are not passing?

[leogrosa]

@Gui-FernandesBR, the test that fails is tests/integration/test_flight.py::test_time_overshoot.
This is the stack trace:

self = <rocketpy.mathutils.function.funcify_method.<locals>.funcify_method_decorator object at 0x12035b9e0>
instance = <Flight(rocket= <rocketpy.rocket.rocket.Rocket object at 0x16369cd40>, environment= <rocketpy.environment.environment.Environment object at 0x1636407d0>, rail_length= 5.2, inclination= 85, heading = 0,name= Flight)>
owner = <class 'rocketpy.simulation.flight.Flight'>

    def __get__(self, instance, owner=None):
        if instance is None:
            return self
        cache = instance.__dict__
        try:
            # If cache is ready, return it
>           val = cache[self.attrname]
E           KeyError: 'x'

rocketpy/mathutils/function.py:3531: KeyError

During handling of the above exception, another exception occurred:

self = <rocketpy.mathutils.function.funcify_method.<locals>.funcify_method_decorator object at 0x12035b9e0>
instance = <Flight(rocket= <rocketpy.rocket.rocket.Rocket object at 0x16369cd40>, environment= <rocketpy.environment.environment.Environment object at 0x1636407d0>, rail_length= 5.2, inclination= 85, heading = 0,name= Flight)>
owner = <class 'rocketpy.simulation.flight.Flight'>

    def __get__(self, instance, owner=None):
        if instance is None:
            return self
        cache = instance.__dict__
        try:
            # If cache is ready, return it
            val = cache[self.attrname]
        except KeyError:
            # If cache is not ready, create it
            try:
                # Handle methods which return Function instances
>               val = self.func(instance).reset(*args, **kwargs)
E               AttributeError: 'numpy.ndarray' object has no attribute 'reset'. Did you mean: 'repeat'?

rocketpy/mathutils/function.py:3536: AttributeError

During handling of the above exception, another exception occurred:

mock_show = <MagicMock name='show' id='5282258032'>, calisto_robust = <rocketpy.rocket.rocket.Rocket object at 0x16369cd40>
example_spaceport_env = <rocketpy.environment.environment.Environment object at 0x1636407d0>

    @pytest.mark.slow
    @patch("matplotlib.pyplot.show")
    def test_time_overshoot(mock_show, calisto_robust, example_spaceport_env):  # pylint: disable=unused-argument
        """Test the time_overshoot parameter of the Flight class. This basically
        calls the all_info() method for a simulation without time_overshoot and
        checks if it returns None. It is not testing if the values are correct,
        just if the flight simulation is not breaking.
    
        Parameters
        ----------
        calisto_robust : rocketpy.Rocket
            The rocket to be simulated. In this case, the fixture rocket is used.
            See the conftest.py file for more information.
        example_spaceport_env : rocketpy.Environment
            The environment to be simulated. In this case, the fixture environment
            is used. See the conftest.py file for more information.
        """
    
        test_flight = Flight(
            rocket=calisto_robust,
            environment=example_spaceport_env,
            rail_length=5.2,
            inclination=85,
            heading=0,
            time_overshoot=False,
        )
    
>       assert test_flight.all_info() is None

tests/integration/test_flight.py:256: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
rocketpy/simulation/flight.py:3407: in all_info
    self.info()
rocketpy/simulation/flight.py:3403: in info
    self.prints.all()
rocketpy/prints/flight_prints.py:402: in all
    self.initial_conditions()
rocketpy/prints/flight_prints.py:56: in initial_conditions
    f"Position - x: {self.flight.x(t_init):.2f} m | "
rocketpy/mathutils/function.py:3540: in __get__
    val = Function(source, *args, **kwargs)
rocketpy/mathutils/function.py:147: in __init__
    self.set_source(self.source)
rocketpy/mathutils/function.py:264: in set_source
    self.set_interpolation(self.__interpolation__)
rocketpy/mathutils/function.py:309: in set_interpolation
    self.__update_interpolation_coefficients(self.__interpolation__)
rocketpy/mathutils/function.py:324: in __update_interpolation_coefficients
    self.__interpolate_spline__()
rocketpy/mathutils/function.py:1872: in __interpolate_spline__
    c = linalg.solve_banded(
venv/lib/python3.12/site-packages/scipy/linalg/_basic.py:596: in solve_banded
    b1 = _asarray_validated(b, check_finite=check_finite, as_inexact=True)
venv/lib/python3.12/site-packages/scipy/_lib/_util.py:537: in _asarray_validated
    a = toarray(a)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

a = array([ 0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,
        0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,... 0.,  0.,  0.,
        0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,
        0.,  0.,  0.,  0.,  0.])
dtype = None, order = None

    @set_module('numpy')
    def asarray_chkfinite(a, dtype=None, order=None):
        """Convert the input to an array, checking for NaNs or Infs.
    
        Parameters
        ----------
        a : array_like
            Input data, in any form that can be converted to an array.  This
            includes lists, lists of tuples, tuples, tuples of tuples, tuples
            of lists and ndarrays.  Success requires no NaNs or Infs.
        dtype : data-type, optional
            By default, the data-type is inferred from the input data.
        order : {'C', 'F', 'A', 'K'}, optional
            Memory layout.  'A' and 'K' depend on the order of input array a.
            'C' row-major (C-style),
            'F' column-major (Fortran-style) memory representation.
            'A' (any) means 'F' if `a` is Fortran contiguous, 'C' otherwise
            'K' (keep) preserve input order
            Defaults to 'C'.
    
        Returns
        -------
        out : ndarray
            Array interpretation of `a`.  No copy is performed if the input
            is already an ndarray.  If `a` is a subclass of ndarray, a base
            class ndarray is returned.
    
        Raises
        ------
        ValueError
            Raises ValueError if `a` contains NaN (Not a Number) or Inf (Infinity).
    
        See Also
        --------
        asarray : Create and array.
        asanyarray : Similar function which passes through subclasses.
        ascontiguousarray : Convert input to a contiguous array.
        asfortranarray : Convert input to an ndarray with column-major
                         memory order.
        fromiter : Create an array from an iterator.
        fromfunction : Construct an array by executing a function on grid
                       positions.
    
        Examples
        --------
        >>> import numpy as np
    
        Convert a list into an array. If all elements are finite, then
        ``asarray_chkfinite`` is identical to ``asarray``.
    
        >>> a = [1, 2]
        >>> np.asarray_chkfinite(a, dtype=float)
        array([1., 2.])
    
        Raises ValueError if array_like contains Nans or Infs.
    
        >>> a = [1, 2, np.inf]
        >>> try:
        ...     np.asarray_chkfinite(a)
        ... except ValueError:
        ...     print('ValueError')
        ...
        ValueError
    
        """
        a = asarray(a, dtype=dtype, order=order)
        if a.dtype.char in typecodes['AllFloat'] and not np.isfinite(a).all():
>           raise ValueError(
                "array must not contain infs or NaNs")
E           ValueError: array must not contain infs or NaNs

venv/lib/python3.12/site-packages/numpy/lib/_function_base_impl.py:646: ValueError

[leogrosa]

I noticed that the same test also fails when running the tests on the develop branch. Maybe it's a problem with my computer — I'll investigate further.
This makes me believe that this PR is ok and ready to be merged.

[Gui-FernandesBR]

@leogrosa , tests are running on CI, this is likely a problem on your own end, your environment is probably not configured as it should be. I don't see how this could be a problem introduced by this PR, I'm sorry.

My recommendation is for you to share your problem with the team during the regular meeting time so you can all debug it together.